2016/08/31 by A. C. Hewson
Materials Science · Physics and Astronomy · #Condensed matter physics #Density functional theory #Dynamical mean field theory #Hubbard model #Iron-based superconductors research #Mathematical physics #Mean field theory #Omega #Perturbation theory (quantum mechanics) #Physics #Physics of Superconductivity and Magnetism #Quantum electrodynamics #Quantum mechanics #Quasiparticle #Rare-earth and actinide compounds #Renormalization #Renormalization group #Scattering #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.94.195152
published as Phys. Rev. B 94, 195152 (2016) · 13 pages 19 figures
openalex publication_date 2016/11/28 · arxiv created 2016/11/29 · arxiv updated 2016/12/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We calculate the renormalized parameters for the quasiparticles and their interactions for the Hubbard model in the paramagnetic phase as deduced from the low-energy Fermi-liquid fixed point using the results of a numerical renormalization-group calculation (NRG) and dynamical mean-field theory (DMFT). Even in the low-density limit there is significant renormalization of the local quasiparticle interaction \stackrel\ifmmode \else \~\fiU, in agreement with estimates based on the two-particle scattering theory of J. Kanamori [Prog. Theor. Phys. 30, 275 (1963)]. On the approach to the Mott transition we find a finite ratio for \stackrel\ifmmode \else \~\fiU/\stackrel\ifmmode \else \~\fiD, where 2\stackrel\ifmmode \else \~\fiD is the renormalized bandwidth, which is independent of whether the transition is approached by increasing the on-site interaction U or on increasing the density to half filling. The leading \ensuremathω2 term in the self-energy and the local dynamical spin and charge susceptibilities are calculated within the renormalized perturbation theory (RPT) and compared with the results calculated directly from the NRG-DMFT. We also suggest, more generally from the DMFT, how an approximate expression for the q,\ensuremathω spin susceptibility \ensuremathχ(q,\ensuremathω) can be derived from repeated quasiparticle scattering with a local renormalized scattering vertex.